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ARS Home » Southeast Area » Auburn, Alabama » Aquatic Animal Health Research » Research » Publications at this Location » Publication #268723

Title: Identification and expression profiles of multiple genes in Nile tilapia in response to bacterial infections

Author
item Wei Pridgeon, Yuping
item AKSOY, MEDIHA - Tuskegee University
item Klesius, Phillip
item LI, YUEHONG - Jilin Agricultural University
item MU, SINGJIANG - Auburn University
item SRIVASTAVA, KUNWAR - Tuskegee University
item REDDY, GOPAL - Tuskegee University

Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2011
Publication Date: 9/30/2011
Citation: Wei Pridgeon, Y., Aksoy, M., Klesius, P.H., Li, Y., Mu, S., Srivastava, K., Reddy, G. 2011. Identification and expression profiles of multiple genes in Nile tilapia in response to bacterial infections. Veterinary Immunology and Immunopathology. 144:111-119.

Interpretive Summary: To understand how Nile tilapia responds to bacterial infection at molecular level, a subtractive library was constructed. A total of 31 unique genes were identified from the subtractive library. Nine of the 31 ESTs were significantly induced in Nile tilapia at 6h post infection with A. hydrophila at an injection dose that caused ~20% mortality. Of the nine induced genes, four were also significantly induced in Nile tilapia at 6h post infection with A. hydrophila at an injection dose that caused ~60% mortality. Of the four genes induced by A. hydrophila at both injection doses, three were also significantly induced at 6h post infection with Streptococcus iniae at dose that caused ~70% or ~30% mortality. The three genes induced by both bacteria included one gene similar to adenylate kinase domain containing protein 1), an unknown gene that shared similarity with Salmo salar IgH, and another unknown gene. Significantly upregulation of these genes in Nile tilapia following bacterial infections suggested that they might play important roles in host defense against bacterial infections.

Technical Abstract: To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophila. A total of 31 unique expressed sequence tags (ESTs) were identified from 192 clones of the subtractive cDNA library. Quantitative PCR revealed that nine of the 31 ESTs were significantly (P<0.05) upregulated in Nile tilapia at 6h post infection with A. hydrophila at an injection dose of 105 CFU per fish (~20% mortality). Of the nine upregulated genes, four were also significantly (P<0.05) induced in Nile tilapia at 6h post infection with A. hydrophila at an injection dose of 106 CFU per fish (~60% mortality). Of the four genes induced by A. hydrophila at both injection doses, three were also significantly (P<0.05) upregulated in Nile tilapia at 6h post infection with Streptococcus iniae at doses of 106 and at 105 CFU per fish (~70% and ~30% mortality, respectively). The three genes induced by both bacteria included EST 2A05 (similar to adenylate kinase domain containing protein 1), EST 2G11 (unknown protein, shared similarity with Salmo salar IgH locus B genomic sequence with e value of 0.02), and EST 2H04 (unknown protein). Significantly upregulation of these genes in Nile tilapia following bacterial infections suggested that they might play important roles in host response to bacterial infections.